Well seeing how this game was just funded to be created, I know it is premature to start planning ideas for sequels, but if they do plan on making a series at all, they need to start making these decisions now.
If the game is to be decision based, it will be impossible to design a sequel that will be customized based on the players decisions without carrying over a save of some sort. WIthout carrying over a save, all the connections to the first game will be generic and you lose an opportunity to connect the player to the game world that much more.
For example, tThere were some big decisions required of you in Dragon Age, but upon playing the sequel, I was extremely disappointed to learn that those decisions were not connected in any way, and you never got the payoff of seeing how your decisions affected the world. This sucked the life out of the sequel for me as I knew my decisions were meaningless in the big picture. I know it's hard to implement with the uncertainty of any sequels, but it would be a huge boost to the depth of the game.